1. Field of the Invention
The present invention relates to an alternating current power source apparatus which controls an AC output of an AC generator driven by an engine equipped in a car etc. to a desired voltage and a desired frequency.
2. Description of the Prior Arts
In the conventional apparatus, an AC generator driven by an internal combustion engine equipped in a car etc., usually outputs a relatively low voltage (such as 12 V, 24 V or 50 V) which is lower than a required alternating voltage (such as 100 V) and the output is rectified to the direct current so as to charge a battery in the car and the direct voltage is intermittently changed in a constant frequency (such as 50 or 60 Hz) so as to feed it as a primary input of a transformer whereby an alternating power source having a desired voltage (such as 100 V) and a desired frequency (such as 50 or 60 Hz) is formed in the secondary side.
However, in accordance with the conventional DC-AC converter system, the generator generates the alternating current and the alternating current is rectified to the direct current and the direct current is further converted to the alternating current by the chopper and the alternating current is further boosted by the transformer to obtain a desired voltage. This is the ineffective system.
Various devices such as the rectifier for converting the alternating current to the direct current and the chopper for converting the direct current to the alternating current and the transformer for boosting the voltage are needed in the conventional system. Accordingly, the apparatus is heavy and expensive and has a large size and low efficiency and low reliability. These are disadvantages which prevent the practical application in the car market.